Pytorch where index 在本地运行 PyTorch 或通过受支持的云平台快速开始. Jan 4, 2023 · 本文详细介绍了torch. Intro to PyTorch - YouTube Series Dec 8, 2018 · So first let me describe my use case. requires_grad_(True) # create index ranges x_range = torch. location/coordinate) of the first occurence of value in Tensor. torch. All index types such as None / / integer / boolean / slice / tensor are available in the C++ API, making translation from Python indexing code to C++ very simple. What you can do is to apply your condition and get a binary mask of indices that match the condition and find the indices using torch. See also torch. Return a tensor of elements selected from either input or other, depending on condition. PyTorch 入门 - YouTube 系列. where(condition, input, other) → Tensor condition: The boolean tensor that controls selection. where(condition) is identical to torch. 6. nonzero (). where 函数是一种强大的工具，用于根据条件从两个张量中选择元素。这个函数在数据处理和神经网络的正则化技术中特别有用，比如实现dropout或者masking策略。torch. Syntax torch. Apparently, T[:, L] gives a tensor of shape (x, x), where every element of L indexes every row. Each index tensor corresponds to a dimension of the source tensor. (Note that torch does not support argmax for "bool" tensors, and so comp needed to be cast to another data type. where 的基本用法类似于Python的内建函数 np. Please use pip Jul 10, 2023 · As a data scientist or software engineer, you may often work with large datasets and complex mathematical operations that require efficient and scalable computing. Familiarize yourself with PyTorch concepts and modules. Intro to PyTorch - YouTube Series Apr 9, 2022 · pytorch中index_select函数的作用选取某一维度上的数据 函数形式为： index_select(input, dim, index) input为tensor，dim是维度从0开始，index是一维tensor（向量），表示在这个维度上要选择的下标 下边直接上例子： import torch x = torch. nonzero(). PyTorch via Anaconda is not supported on ROCm currently. 2. 熟悉 PyTorch 的概念和模块. In this article, we will dive deep into PyTorch tensor indexing, a powerful technique that allows you Feb 27, 2025 · In PyTorch, the . This can be done quite simply with argmax: it will return the index of the first "1" (or if all the values are "0", will return the first index, ie, 0). arrays/lists) it returns the indices of the occurrences of the value you are looking for. PyTorch 教程中的新增内容. Learn the Basics. 3w次，点赞9次，收藏32次。本文详细介绍Tensor在PyTorch中的基本索引操作，包括初级索引如选取行、列和元素，以及高级索引如使用index_select、masked_select、non_zero和gather函数进行复杂的数据筛选和处理。 Nov 17, 2018 · I have a tensor T of shape (x, y) and a list L of shape (x), containing numbers [0, y). PyTorch 食谱. zeros((1, 400, 400)). index_select (input, dim, index, *, out = None) → Tensor ¶ Returns a new tensor which indexes the input tensor along dimension dim using the entries in index which is a LongTensor . I want to have a tensor of shape (x), where each the ith element is T[i, L[i]]. index_put_: This operation puts the value of ‘val’ into the self tensor using the indices of the given ‘index’. out (Tensor, optional) – the output tensor. nonzero. where() 的两种用法，第一种是最常规的，也是官方文档所注明的；第二种就是配合 bool 型张量的计算. 7. For flat tensors (i. 学习基础知识. With ROCm. Thanks, @Nikronic. By comparing each element of the tensor with the desired value, we can obtain the indices of the matching elements. 0 index的shape本来是(2,2), 里面的每个value被expand成了一个(3,4)的tensor, 故最后结果为shape为(2,2,3,4)的tensor. Syntax: index_put_(indices, values, accumulate=False) → Tensor Mar 13, 2023 · 文章浏览阅读4. 教程. We use the prepared index tensors to directly select the desired elements from source_tensor. requires Mar 12, 2025 · source_tensor[batch_indices, index_tensor_expanded, embedding_indices] This is advanced indexing. 4k次，点赞15次，收藏9次。文章详细介绍了torch. where，但它专门针对PyTorch张量进行了优化。 May 12, 2018 · Here is a solution if you want to index a tensor in an arbitrary dimension and select a set of tensors from that dimension (an example is say we want to compute some average of the first 3 layers): Jul 18, 2021 · 6. 我们先看 官方文档 的解释： Jun 12, 2020 · I meet a problem that, how to get the index of a element in a Tensor whose value is True? Such as, a Tensor like: False False Fasle Flase True False False False False Then I can get the index of (1,1). The operation is defined as: The tensors condition, input, other must be broadcastable. nonzero(condition, as_tuple=True). r. 1. Mar 28, 2022 · def index(tensor: Tensor, value, ith_match:int =0) -> Tensor: """ Returns generalized index (i. May 12, 2020 · torch uses same convention as numpy such for finding values or indices of particular tensor regarding specific condition. This really solves it. Indexing a tensor in the PyTorch C++ API works very similar to the Python API. bests. I have a tensor of shape NxCxseq_len. I have an index tensor of shape NxK (basically K from each batch) where K denotes the indices from the seq_len axis and I need to pick these specific samples. Often, the latest CUDA version is better. 可随时部署的 PyTorch 代码示例，小巧精悍. Run PyTorch locally or get started quickly with one of the supported cloud platforms. Currently, I’m using this Run PyTorch locally or get started quickly with one of the supported cloud platforms. Tutorials. Preparing Index Tensors Jul 19, 2020 · 文章浏览阅读3. Bite-size, ready-to-deploy PyTorch code examples. index_select(input, dim, index) Returns a new tensor which indexes the input tensor along dimension dim using the entries in index which is a LongTensor. So how can I implement this operation? Your answer and idea will be appreciated! Feb 27, 2025 · In PyTorch, the . where and torch. The returned tensor has the same number of dimensions as the original tensor ( input ). double() tensor. index_fill: This is the out of place index-based operation for filling the elements with tensor with ‘val’. Pytorch 如何获取Pytorch张量中特定值的索引 在本文中，我们将介绍如何使用Pytorch张量获取特定值的索引。Pytorch是一个开源的深度学习框架，它提供了很多方便的函数和方法来处理张量，并且支持各种计算设备，如CPU和GPU。 Jun 28, 2021 · The second line needs to find the "index of the first match". where function returns a new tensor with elements chosen based on a condition, selecting values from one source when the condition is met and from another when it is not. double() x_range. Github; Table of Contents. Then, run the command that is presented to you. where()函数的两种用法，一种是三参数形式，用于在满足条件时选择tensor的元素；另一种是一参数形式，返回满足条件的tensor索引。 May 7, 2018 · I want to do something like this, but I need it be be differentiable w. ) Mar 12, 2020 · 在PyTorch中，torch. 通过我们引人入胜的 YouTube 教程系列掌握 PyTorch 基础知识 Jan 10, 2023 · 6年pytorch开发经验，资深pytorch开发者，专栏包括pytorch环境，构建训练框架，项目部署，等相关知识，从基础知识到高阶技巧，各种算法项目开发实践经验， 通俗易懂的示例代码，详尽的踩坑记录。精华知识分享，绝对物超所值。 Run PyTorch locally or get started quickly with one of the supported cloud platforms. e. Whats new in PyTorch tutorials. Apr 26, 2022 · 使用 index_select 函数输出的张量维度和原始的输入张量维度相同。这也是为什么即使在对输入张量的其中一个维度的一个索引号进行索引 (此时可以使用基本索引和切片索引) 时也需要使用 PyTorch 中的高级索引方式才能与 index_select 函数等价的原因所在；. matmul() function Find the min and max in a tensor Find Mar 13, 2022 · 6年pytorch开发经验，资深pytorch开发者，专栏包括pytorch环境，构建训练框架，项目部署，等相关知识，从基础知识到高阶技巧，各种算法项目开发实践经验， 通俗易懂的示例代码，详尽的踩坑记录。精华知识分享，绝对物超所值。 To install PyTorch via Anaconda, and you do have a CUDA-capable system, in the above selector, choose OS: Linux, Package: Conda and the CUDA version suited to your machine. PyTorch is a popular open-source machine learning library that offers fast and flexible tensor computation with GPU acceleration. Intro to PyTorch - YouTube Series Tensor Indexing API¶. Example: torch. index_select和gather pytorch说明: index_select; gather. is there any possibility to achieve this? import torch # initialize tensor tensor = torch. arange(150, 250). Jul 23, 2023 · What are tensors? Create a tensor from a Python list NumPy arrays and PyTorch tensors manual_seed() function Create tensors with zeros and ones Tensors comparison Change the data type of a tensor Create Random Tensors Shape, dimensions, and element count Create a tensor range Determine the memory usage of a tensor Transpose a tensor torch. where ()函数在PyTorch中的两种主要用法。 第一种是根据给定的条件选择张量的元素，创建新的张量。 当条件为True时，选择x的值，否则选择y的值。 第二种特殊用法是当输入为bool型张量时，返回元素同时满足条件的行和列索引。 文章通过示例展示了形状相同、不同以及标量情况下的使用，并强调了广播机制的重要性。 摘要生成于 C知道 ，由 DeepSeek-R1 满血版支持， 前往体验 > 本文主要讲述 torch. PyTorchのTensorは多次元配列であり、各要素にはインデックスが割り当てられています。特定の値のインデックスを取得するには、いくつかの方法があります。 Learn about PyTorch’s features and capabilities. I need this to be differentiable, and ideally with only pure torch operations and without loops. t the index-tensors. Jul 6, 2024 · Finding the index of a specific value in PyTorch tensors can be achieved using the == operator, nonzero() function, and item() function. requires_grad_(True) y_range = torch. double() y_range. PyTorch Recipes. Syntax, parameters are the same as the above. ypkrwt qzyquq wgjqe pbf xubgq rticho zmkurmp fbg ctdwjle rlbkv ajkp uwcej pgvta cdbv uww